Three Phase 440 - 220 Rewire?

[lt1yj]

I searched here and on the internet but cannot find info on rewiring a three phase motor from 440V (480) to 220V (240). I have 220 3 phase at my shop but two new machines I just purchased came from a shop wired 440.

Can someone point me to a website or a book I can buy to learn this from? Or even a wiring diagram? Any help is appreciated.

I can't wait to get these hooked up so I can start making chips.

[big97redtj]

If you pop the cover plate off of the motor where the terminations are, there should be a schematic.


Or it should be on the motor nameplate itself.

[lt1yj]

First place I looked. No schematic on the inside of the cover and the motor tag just has the basic info no schematic.

I know what you're saying though. I have seen the schematic on another data plate, now I need to go look at the other machines in my shop. Should have thought of that first.

[iroc-cj]

One thing to add, if your machines have lower voltage control make sure you reconfigure your control transformer for 220v

[lt1yj]

Ok,

Checked the other machines in my shop and found a readable schematic. I rewired one of the machines and fired it up. Only took 5 minutes to do. The wires were labled 1-9 and simple.

Second machine has a reversing switch. The switch goes to a 3x3 terminal grid. The wires weren't labeled so I took an educated guess based on the schematic from the other motor. I guess I got lucky becuase it fired right up and runs both directions.

I do have a transformer that just runs a work light. I planned to just wire it to a 110 plug instead of the transformer, then disconnect the transformer. Any reason not to?

[peesalot]

look on the motor leads ( the wires) sometimes the voltage # is printed on the leads you use for that voltage. Those are gonna suck some juice on 3 phase 220 so set your amperage correctly , meaning use right wire size and breaker so they don't heat up.

[JeepRecoveryTeam]

PM 025 here on the board. He just wired his shop with 3 phase.


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[Gummi Bear]

If the motor has a 9 wire peckerhead (this is what you call the box on the outside of the motor where the terminations belong)

And it was wired for 480

Your phase wires are as follows - brown(A phase), orange(B phase), yellow(C phase)) should be to wires labeled 1, 2, 3 respectively; with 4 to 7, 5 to 8, 6 to 9 wired together. This is common high voltage motor wiring.



For low voltage it will be as following:

Tie phase leads to 4(A phase), 5(B phase), 6(C phase)

1 to 7, 2 to 8, 3 to 9 tied together.

Don't forget your ground!


Note: The most important part of any motor is the nameplate. Check the data given on the plate before making the connections.

Peesalot is correct, in that your efficiency will be reduced, and your load will increase.


What is the HP rating of the motor? Does the nameplate have suggested max ampacity (FLA)? Does the motor require a starter (contactor with thermal overload protection devices)? It's not as simple as just swapping over wires. Do you need to provide a new disconnect? Size your fuses properly also.

Also note: some cities require the "B" phase to be labeled with a violet color, instead of orange.

[Gummi Bear]

If you have any other questions, you can PM me. If you feel uncomfortable or unsure, call an electrician. An $80per hour service call beats the hell out of a smoked motor and damaged equipment.



Be safe whatever you do, make damn good and sure the power is off before working on it, and label it so that nobody tries to turn it on while you are working on it.

[Jrod-13]

there are several ways to reduce voltage, depending on the wire configureration. The primary reason for reducing voltage is for s soft start, reducing the current while the motor accelerates.

6 wire motors.
These can be wired in either wye or delta. for changing the voltage. ie; 208 on delta or 120 on wye. and 460 on delta, or 265 on wye. They also can be wired in both wye and delta for soft starting.

9 wire motors.
9 wire motors hace two coils per phase, and can be wired in wye or delta, but not both. you can either run the coils in series for 460V or in parrallel for 230V.

12 wire motors.
12 lead wye motors are similar to six lead motors, except there are two coils per phase. Thus, the 12 lead motor has dual voltage ratings and, like the 9 lead motor, the pahse coils would be connected in series for high voltage and in parrallel for low voltage.
12 lead delta motors are also dual voltage, but they are used where reduced voltage starting is desired. The coils would be connected in wye to start, and in delta to run.

clear as mud?